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| United States Patent |
5,190,909
|
|
Shanton
, et al.
|
March 2, 1993
|
Record material utilizing a vinyl carbinol or derivative thereof as a
chromogenic compound
Abstract
Pressure- or heat-sensitive record material utilizes a chromogenic material
of the formula (I) (Ia or Ib):
##STR1##
in which: one of A.sub.1 and A.sub.3 is an optionally-substituted
carbocyclic aryl group and the other of A.sub.1 and A.sub.3 is either an
optionally-substituted aryl group which is the same as or different from
A.sub.1, or an optionally-substituted nitrogen-containing aromatic
heterocyclic group, with the proviso that if both A.sub.1 and A.sub.3 are
aryl groups, then at least one of A.sub.1 and A.sub.3 has a substituted
amino or -N-heterocyclic substituent in the 4- position (relative to the
bond joining A.sub.1 or A.sub.3 respectively to the remainder of the
molecule);
A.sub.2 is hydrogen or an optionally-substituted aryl, alkyl or aralkyl
group; and
A.sub.4 is hydrogen or an optionally-substituted alkyl, aryl or aralkyl
group.
| Inventors:
|
Shanton; Kenneth J. (Neenah, WI);
Azizian; Farid (Oxon, GB2)
|
| Assignee:
|
The Wiggins Teape Group Limited (Basingstoke, GB2)
|
| Appl. No.:
|
613018 |
| Filed:
|
November 15, 1990 |
Foreign Application Priority Data
| Current U.S. Class: |
503/218; 427/150; 427/151; 503/223; 503/224 |
| Intern'l Class: |
B41M 005/136; B41M 005/30 |
| Field of Search: |
427/150,151
503/218,223,224
|
References Cited
U.S. Patent Documents
| 3930108 | Dec., 1975 | Alsop | 427/151.
|
| Foreign Patent Documents |
| 0154528 | Sep., 1985 | EP | 428/411.
|
| 0315901 | May., 1989 | EP | 503/218.
|
| 2362956 | Jul., 1974 | DE | 503/218.
|
| 2212788 | Jul., 1974 | FR | 503/218.
|
| 2294055 | Jul., 1976 | FR | 503/218.
|
| 1432505 | Apr., 1976 | GB | 503/227.
|
| 1456208 | Nov., 1976 | GB | 503/218.
|
| 1465669 | Feb., 1977 | GB | 503/218.
|
Other References
Sisti et al., "A Convenient General Method for the Preparation of
Aldehydes.II", Journal of Organic Chemistry, Jan., 1962.
Akiyama et al., "Diphenylmethane and Triphenylmethane Dye . . .
Near-Infrared", 9 Dyes and Pigments 459-66 (1988).
Gautier et al., "Condensation du Dimsylsodium Avec les . . . ", Tetrahedron
Letters No. 12, 895-98 (1970).
Gilman et al., "Addition Reactions of Organometallic Compounds With
Conjugated Systems", 63 Journal of the American Chemical Society 2046-48
(Aug. 1941).
Lutz et al., "The Effect of Configuration on the Reactivity of the Chalcone
System", 77 Journal of the American Chemical Society 1814-18 (Apr., 1955).
Miocque et al., "Synthese et etude pharmacologique de derives du naphtyl-2
methylsulfoxyde", Chimie Therapeutique, 1972, Jul.-Aug., No. 4.
|
Primary Examiner: Hess; B. Hamilton
Attorney, Agent or Firm: Burns, Doane, Swecker & Mathis
Claims
We claim:
1. Record material comprising a support and at least one chromogenic
material and at last one colour developer therefore, wherein said
chromogenic material includes at least one compound selected from the
compounds represented by the formula (I) (Ia or (Ib):
##STR12##
wherein one of A.sub.1 and A.sub.3 is an optionally-substituted
carbocyclic aryl group and the other of A.sub.1 and A.sub.3 is either an
optionally-substituted aryl group which is the same or different from
A.sub.1, or an optionally-substituted nitrogen-containing aromatic
heterocyclic group, with the proviso that if both A.sub.1 and A.sub.3 are
aryl groups, then at least one of A.sub.1 and A.sub.3 has a substituted
amino or -N-heterocyclic substituent in the 4-position, relative to the
bond joining A.sub.1 or A.sub.1 respectively to the remainder of the
molecule; A.sub.2 is hydrogen or an optionally-substituted aryl, alkyl or
aralkyl group; and A.sub.4 is hydrogen or an optionally-substituted alkyl,
aryl or aralkyl group.
2. Record material as claimed in claim 1, wherein A.sub.1 is a phenyl group
substituted in the 4-position with an alkyl, ether, halo, substituted
amino, -N-heterocyclic, or other nitrogen-containing heterocyclic group.
3. Record material as claimed in claim 1, wherein A.sub.1 is an
unsubstituted phenyl or naphthyl group.
4. Record material as claimed in claim 1, wherein A.sub.3 is a phenyl or
naphthyl group substituted in the 4-position with an alkyl, ether, halo,
substituted amino, -N-heterocyclic or other nitrogen-containing
heterocyclic group.
5. Record material as claimed in claim 1, wherein A.sub.1 or A.sub.3 is a
3-carbazolyl, 4-pyridinyl or 3-indolyl group.
6. Record material as claimed in claim 1, wherein A.sub.3 is an
unsubstituted phenyl or naphthyl group.
7. Record material as claimed in claim 1, wherein A.sub.2 is hydrogen, a
bulky alkyl group, or a phenyl group which is unsubstituted or substituted
with an alkyl or an ether group.
8. Record material as claimed in claim 7, wherein the bulky alkyl group is
a tertiary butyl or cyclopentylmethyl group.
9. Record material as claimed in claim 1, wherein A.sub.4 is hydrogen, an
alkyl group, or a phenyl group which is unsubstituted or substituted with
a nitro group.
10. Record material as claimed in claim 1, wherein one of A.sub.1 and
A.sub.3 is a phenyl or naphthyl group substituted in the 4-position with
an ether group, and the other of A.sub.1 and A.sub.3 is a phenyl or
naphthyl group substituted in the 4-position with a substituted amino
group or with an -N-heterocyclic group.
11. Record material as claimed in claim 1, wherein A.sub.1 and A.sub.3 are
the same or different and are a phenyl or naphthyl group substituted in
the 4-position with a substituted amino group or with an -N-heterocyclic
group.
12. Record material as claimed in claim 1, wherein one of A.sub.1 and
A.sub.3 is a phenyl or a naphthyl group which is unsubstituted or
substituted with an alkyl, ether, or halo group, and the other of A.sub.1
and A.sub.3 is a phenyl or naphthyl group substituted in the 4-position
with a substituted amino group or with an -N-heterocyclic group, and
A.sub.2 is an optionally-substituted aryl group.
13. Record material as claimed in claim 1, wherein one of A.sub.1 an
A.sub.3 is a phenyl or naphthyl group which is unsubstituted or
substituted with an alkyl, ether, or halo group, and the other of A.sub.1
and A.sub.3 is a phenyl or naphthyl group substituted in the 4-position
with a substituted amino group or with an -N-heterocyclic group, and
A.sub.2 is a bulky alkyl group.
14. Record material as claimed in claim 13, wherein the bulky alkyl group
and a tertiary butyl or cyclopentylmethyl group.
15. Record material as claimed in claim 1 wherein one of A.sub.1 and
A.sub.3 is a 3-carbazolyl, 4-pyridinyl or 3-indolyl group and the other of
A.sub.1 and A.sub.3 is a phenyl group substituted in the 4-position with a
substituted amino or -N-heterocyclic group or with an ether group.
16. Record material as claimed in claim 15, wherein the -N-heterocyclic
group is a morpholino, piperidino, or pyrrolidino group, or a piperazino
group which may be alkyl-substituted on the second nitrogen atom.
17. Record material as claimed in claim 15, wherein the substituted amino
group is di-substituted, and the substituents are selected from alkyl,
aryl or aralkyl.
18. Record material as claimed in claim 1, wherein the -N-heterocyclic
group is a morpholino, piperidino, or pyrrolidino group, or a piperazino
group which may be alkyl-substituted on the second nitrogen atom.
19. Record material as claimed in claim 1, wherein the substituted amino
group is di-substituted, and the substituents are selected from alkyl,
aryl or aralkyl groups.
20. Record material as claimed in claim 1, wherein A.sub.1 is a phenyl
group substituted in the 2-position with an alkyl group.
Description
This invention relates to record material utilising a vinyl carbinol or a
derivative thereof as a chromogenic compound. The record material may be
pressure-sensitive or heat-sensitive, and in either case, image formation
occurs by a reaction between the chromogenic material and a suitable
colour developer to produce a coloured species.
As is well known in the art, pressure sensitive record material typically
functions by separating the colour reactive components by a pressure
rupturable barrier. Most commonly this barrier is provided by
microencapsulating a solution in a suitable organic solvent of one of the
reactive components. On application of imaging pressure the microcapsules
are ruptured, liberating the solution of one of the reactive components
into reactive contact with the other component thereby forming a coloured
mark or image corresponding to the applied imaging pressure. It is also
known to use other forms of pressure rupturable barrier such as a
dispersion of a solution in a waxy continuous layer or a honeycomb
structure instead of microcapsules.
Such pressure sensitive record material can be of two basic types: the
so-called "transfer" and "self-contained" types. In the transfer type the
reactive components are present in coatings on facing surfaces of upper
and lower sheets, the coating on the lower surface of the upper sheet
comprising the isolated and usually microencapsulated solution of one
reactive component and the coating on the upper surface of the lower sheet
comprising the other component. Most commonly it is the chromogenic
material which is present in the microcapsules in the coating on the lower
surface of the upper sheet and the colour developer which is present in
the coating on the upper surface of the lower sheet. This is the so-called
"normal transfer" pressure sensitive system. An alternative to this is the
so-called "reverse transfer" system in which the colour developer is
dissolved and microencapsulated and the chromogenic material is present,
usually adsorbed on a suitable particulate carrier, in the coating on the
upper surface of the lower sheet.
The sheets carrying microencapsulated material on their lower surfaces are
usually referred to as "CB" (coated back) sheets and the sheets carrying a
reactive coating on their upper surfaces are usually referred to as "CF"
(coated front) sheets. In addition it is common to use intermediate sheets
which carry appropriate coatings on both upper and lower surfaces and
these are usually referred to as "CFB" (coated front and back) sheets.
In self-contained pressure sensitive sheet record material, both reactive
components are present on or in a single sheet. Premature reaction is
inhibited by microencapsulating one of the components, usually the
electron donating chromogenic material. The reactive components can be
present in one or more coatings on a surface of the sheet (coated
self-contained) or dispersed within the body of the sheet (loaded
self-contained).
In heat sensitive sheet record material, the reactive components, i.e. the
chromogenic material and the colour developer are initially present in a
mutually unreactive state and are then enabled to react together by
changes brought about by heat. Most commonly this is achieved by including
the chromogenic material and colour developer in the heat sensitive record
material as solids. On heating the record material, the chromogenic
material and/or the colour developer and/or another component of the
system melts and thus permits reactive contact between the chromogenic
material and colour developer. As an alternative to the arrangement just
described, the chromogenic material and the colour developer may be
microencapsulated in solution in a similar manner as for pressure
sensitive record material. Imaging then occurs on heat-induced rupture or
increased wall permeability of the capsules.
Numerous chromogenic compounds have been used or proposed for use in record
material as described above. Examples of commercially successful
chromogenic compounds include phthalides such as
3,3-bis(4-dimethylaminophenyl)-6-dimethylaminophthalide (usually referred
to as crystal violet lactone or CVL); indolyl phthalides such as
3,3-bis(1-N-ethyl-2-methylindol-3-yl)phthalide, fluorans, particularly
amino-substituted fluorans such as
3-(N-methyl-N-cyclohexylamino)-6-chloro-7-methylfluoran and
3-diethlamino-6-methyl-7-N-phenylaminofluoran; and spirodipyrans such as
3'-i-propyl-7-dibenzyl-amino-2,2'-spirodi[2-1-benzopyran].
A number of suggestions have been made to use the carbinol bases of
dyestuffs or derivatives of such carbinols, as chromogenic compounds in
pressure sensitive record material. Such carbinols do form colour, but do
so too readily to be useful in practical systems. Typically, the carbinols
will colour up during micro-encapsulation or they are so reactive that
small quantities of extracapsular chromogenic material--inevitable because
encapsulation is not perfectly efficient and some capsules will be
inadvertently broken during handling--produce intense colouration on
reaction with the base paper usually used as the substrate. These are
serious drawbacks.
The present invention is based on our finding that certain substituted
propene carbinols or carbinol derivatives as defined below are good colour
formers which do not suffer from the excessive reactivity typical of
previously proposed carbinol chromogenic compounds. Certain of these
propene carbinol and carbinol derivatives are known per se, although their
utility as chromogenic compounds for use in record materials has not
previously been disclosed. Thus,
1,1-diphenyl-3-(4-dimethylaminophenyl)prop-2-en-1-ol is referred to in an
article by Gilman and Kirby in JACS 63 (1941) 2046 at page 2048.
1-(4-dimethylaminophenyl)-3,3-diphenyl prop-2-en-1-ol is referred to in an
article by Sisti, Burgmaster and Fudim in Journal of Organic Chemistry,
Vol. 27 (1962), pages 279-281. Neither of these articles disclose any
utility for the compounds described. British Patents Nos. 1465669 and
1456208 disclose the use of a broad range of vinyl compounds, including
certain vinyl carbinols or carbinol derivatives in pressure- and heat-
sensitive record materials respectively, but none of the compounds
explicitly exemplified fall within the class of carbinols or carbinols
utilised in the present invention, as defined below. Finally, a broad
class of tri-substituted prop-2-en-1-ols is described for transfer
printing of textiles in British Patent Specification No.1432505.
The present invention provides in a first aspect record material comprising
at least one chromogenic material and at least one colour developer
therefore, characterized in that the chromogenic material includes at
least one compound of the formula (I) (Ia or Ib):
##STR2##
in which:
one of A.sub.1 and A.sub.3 is an optionally-substituted carbocyclic aryl
group, and the other of A.sub.1 and A.sub.3 is either an
optionally-substituted aryl group which is the same as or different from
A.sub.1, or an optionally-substituted nitrogen-containing aromatic
heterocyclic group, with the proviso that if both A.sub.1 and A.sub.3 are
aryl groups, then at least one of A.sub.1 and A.sub.3 has a substituted
amino or -N-heterocyclic substituent in the 4- position (relative to the
bond joining A.sub.1 or A.sub.3 respectively to the remainder of the
molecule);
A.sub.2 is hydrogen or an optionally-substituted aryl, alkyl or aralkyl
group
A.sub.4 is hydrogen or an optionally-substituted alkyl, aryl or aralkyl
group.
The expression "alkyl" as used in this specification includes not just
straight or branched-chain alkyl groups but also cycloalkyl groups.
A.sub.1 is preferably a substituted or unsubstituted phenyl or naphthyl
group. The nature of the substituent group(s), when present, is not
thought to be critical (subject of course to the proviso set out above).
Alkyl, ether, halo, substituted amino and optionally-substituted,
preferably saturated -N-heterocyclic groups are examples of suitable
substituent groups. Substitution is preferably in the 4-position (as
defined above), but in the case of an alkyl group, it can equally well be
in the 2- position When there are two substituent groups, substitution is
preferably in the 2- and 4- positions. When a substituted amino
substituent is present, both hydrogens of the amino group are preferably
substituted (i e. di-substitution), and the substituents on the amino
group are selected from alkyl, aryl and aralkyl groups.
When A.sub.3 is an aryl group, it is preferably a substituted or
unsubstituted phenyl or naphthyl group. As with A.sub.1, the nature of the
substituent group(s), when present, is not thought to be critical (subject
again to the proviso set out above). Alkyl, ether, halo, substituted
amino, and -N-heterocyclic or other nitrogen-containing heterocyclic
groups are examples of suitable substituent groups. Substitution is
preferably in the 4- position (as defined above). When there are two
substituent groups, substitution is preferably in the 2- and 4- positions.
When a substituted amino substituent is present, both hydrogens of the
amino group are preferably substituted (i e. di-substitution), and the
substituents on the amino group are selected from alkyl, aryl and aralkyl
groups. p The expression "ether" as used in this specification includes
cyclic ethers.
When A.sub.1 or A.sub.3 is an optionally-substituted nitrogen-containing
heterocyclic group, it is preferably an -N-heterocyclic group or an
optionally-substituted 3-carbazolyl, 4-pyridinyl or 3-indolyl group. The
optional substitution can be on the nitrogen atom, for example with an
alkyl group, or elsewhere, for example in the 2-position with a phenyl
group.
The -N-heterocyclic substituent groups referred to in the definitions of
A.sub.1 and A.sub.3 above are typically morpholino, piperidino,
pyrrolidino or piperazino groups (the last-mentioned may be
alkyl-substituted on the second nitrogen atom). Saturated -N-heterocyclic
groups are preferred.
The halo substitution referred to in the definition of A.sub.1 and A.sub.3
above is normally with chlorine.
A.sub.2 is preferably hydrogen, a tertiary butyl, cyclopentylmethyl or
other bulky alkyl group or a phenyl group which is unsubstituted or is
substituted with an alkyl or an ether group. By a bulky alkyl group is
meant a group which is sufficiently bulky to displace A.sub.1 from the
spatial position it would otherwise occupy in the molecule.
A.sub.4 is preferably hydrogen, an alkyl group, or a phenyl group which is
unsubstituted or is substituted with a nitro group.
The chromogenic compounds disclosed herein for use in record material give
rise to a wide range of different colours on contact with typical
carbonless paper colour developers. This is a particular benefit of the
invention. The colour obtained in the case of any particular chromogenic
compound is dependent on the chemical nature of the chromogenic compound.
This is discussed further below in relation to a number of preferred
sub-classes of chromogenic compound.
When one of A.sub.1 and A.sub.3 is a phenyl or naphthyl group substituted
in the 4- position with an ether group, and the other of A.sub.1 and
A.sub.3 is a phenyl or naphthyl group substituted in the 4- position with
a substituted amino group or with an -N-heterocyclic group, the developed
colour is generally blue or cyan, although there can be exceptions to this
rule.
When each of A.sub.1 and A.sub.3 is a phenyl or a naphthyl group
substituted in the 4- position with a substituted amino group or with an
-N-heterocyclic group, and A.sub.1 and A.sub.3 are the same or different,
the developed colour is generally blue, cyan or green, although again
there can be exceptions to this rule.
When one of A.sub.1 and A.sub.3 is a phenyl or naphthyl group which is
unsubstituted or is substituted with an alkyl or halo group, A.sub.2 is an
optionally-substituted aryl group or an aralkyl group, and the other of
A.sub.1 and A.sub.3 is a phenyl or naphthyl group substituted in the 4-
position with a dialkylamino group or with an -N-heterocyclic group, the
developed colour is generally red-magenta, magenta, blue-magenta, reddish
blue, purple or blue. The hue obtained is influenced by the substituents
on whichever of A.sub.1 and A.sub.3 is not substituted in the 4- position
with a substituted amino or -N-heterocyclic group.
When A.sub.1 is a phenyl or naphthyl group which is unsubstituted or is
substituted with an alkyl or halo group, A.sub.2 is a tertiary butyl,
cyclopentylmethyl or other bulky alkyl group and A.sub.3 is a phenyl or
naphthyl group substituted in the 4- position with a dialkylamino group or
with an -N-heterocyclic group, the developed colour is generally yellow or
orange.
When one of A.sub.1 and A.sub.3 is a 3-carbazolyl, 4-pyridinyl or 3-indolyl
group and the other of A.sub.1 and A.sub.3 is a phenyl group substituted
in the 4- position with a dialkylamino or -N-heterocyclic group, the
developed colour varies with the nature of the heterocyclic group. For
example, when A.sub.3 is pyridyl, the developed colour is typically yellow
or orange, whereas when A.sub.3 is carbazolyl, the developed colour is
typically blue or green, and when A.sub.3 is indolyl, the developed colour
is typically yellow or green.
Compounds of the general formulae (I) can be made from known starting
materials by synthetic routes involving generally known techniques. We
have successfully used the following route to make compounds of the
formula (Ia) and to convert these to the corresponding compounds of the
formula (Ib). In the sequence outlined below the symbols A.sub.1, A.sub.2,
A.sub.3 and A.sub.4 are as defined for formula (I) above.
Step i
##STR3##
This reaction is a base catalysed condensation followed by elimination of
water. We expect that the elimination of water occurs by a concerted
mechanism such that the intermediate unsaturated ketone is
trans-substituted. This is consistent with our observation from TLC, IR
and NMR data that the intermediate is obtained as a single compound,
rather than a mixture of isomers that would otherwise be expected.
Step ii
(Applicable where A.sub.2 is other than hydrogen)
##STR4##
We believe from TLC and NMR data that this reaction proceeds without
altering the stereochemistry around the double bond. The second reaction
stage is particularly convenient when it is desired to generate the (Ia)
carbinols, since A.sub.4 OH is then water. when A.sub.2 is hydrogen, a
compound of formula (Ia) is conveniently obtained by direct reduction of
the product from Step i above, for example by means of sodium borohydride
in methanol.
Step iii
(Applicable where it is desired to produce a compound of formula (Ib))
##STR5##
where A'.sub.4 is a group of the formula A.sub.4.
The reaction will usually be carried out in one of two ways:
(a) Two Stage
##STR6##
(b) Single Stage
##STR7##
Generally the two stage reaction is easier to control. The two stage
reaction would be expected to generate a mixture of cis- and
trans-products and our NMR observations support this.
A variation on the synthesis of compounds of the formula (Ia) is possible
by "interchanging" A.sub.1 and A.sub.2 in the synthesis, thus:
step i
##STR8##
step ii
##STR9##
The synthesis of compounds of the formula Ib can follow as described above.
This variation is particularly useful where the A.sub.2 Li compound is
difficult to handle, for example where A.sub.2 is an alkyl or aralkyl
group.
As is referred to above, the compounds of the general formula (I) can exist
in cis- and trans- forms (about the ethylenic double bond). We believe
that this isomerism is not of fundamental importance in colour formation.
The particular isomer or the precise proportions in a mixture of cis- and
trans- isomers will depend on the detail of the manufacturing route used.
The compounds of the general formula (I) have two structural isomeric
forms, the "a" and "b" forms of general formulae (Ia) and (Ib) above.
These are related as 1- and 3-allylic carbinols or carbinol ethers. The
colours produced from corresponding "a" and "b" forms are, at least, very
similar (leaving group and stereochemical effects may make them
non-identical in practical use).
The compounds of the general formula (I) will react with typical carbonless
paper colour developers to generate often very intense colours. The most
intense colours available approach the intensity of CVL, which is
recognized as giving a very intense colour, and have absorption peaks
which are very broad, i.e. the peaks cover a large absorption area. Thus
they are potentially very efficient chromogenic compounds. For example,
the compound
1-phenyl-1-(4-piperidinophenyl)-3-(4-methoxyphenyl)prop-2-en-1-ol
(Synthesis Example 4 below) gives a coloured form on an acid-washed
dioctahedral montmorillonite clay CF with .lambda. max=595 nm and a
1/2height peak width of ca. 190 nm (490-680 nm). The absorption intensity
is similar to that of CVL on the same CF on which CVL gives .lambda.
max=616 nm and a 1/2height peak width of ca. 125 nm (525 to 650 nm).
Generally, we have found that the chromogenic compounds of the general
formula (I) form more intense colours more quickly and to give more
intense colours with typical inorganic or mineral carbonless colour
developers than with organic, particularly phenolic resin, colour
developers. In particular, effective inorganic or mineral colour
developers include acid washed montmorillonite colour developers such as
those sold under the trade names "Silton" by Mizusawa Chemical Co.,
"Copisil" by Sud-Chemie AG, and "Fulacolor" by Laporte Industries Ltd., or
semi-synthetic mineral colour developers made by modifying acid washed
montmorillonites.
The chromogenic compounds of the formula (I) can be present in record
material in combination with conventional chromogenic compounds, for
example those referred to earlier in this specification.
The pressure-sensitive record material of the invention typically utilises
paper as a substrate. The pressure rupturable barrier can be provided by
any means known in the art but will usually be provided by dissolving the
chromogenic compound(s) in a suitable, usually oily, solvent and
microencapsulating the solution by any of the encapsulation techniques
known for carbonless paper. Examples include coacervation
microencapsulation, typically using gelatin as a major component of the
capsule wall, interfacial polymerization encapsulation techniques and
synthetic polymer based encapsulation methods not involving interfacial
polymerization notably those of aminoplast encapsulation systems, in
particular those based on ureaformaldehyde or melamine-formaldehyde
materials.
Whilst the compounds of the formula (I) are in general less effective with
organic colour developers than with inorganic colour developers, they are
in principle at least usable with organic colour developers in both
pressure-sensitive and heat-sensitive record material.
The following Examples illustrate the invention. All parts and percentages
are by weight unless otherwise stated. Synthesis Examples (SE) 1 to 68
relate to the synthesis of compounds of the general formula (I).
Application Examples (AE) 1 to 4 relate to investigation of properties
specifically related to pressure sensitive record material and to specific
illustrations of the use of compounds of the general formula (I) in such
record material. Application Example 5 relates to heat-sensitive record
material.
Synthesis Examples 1 to 6, 67 and 68 are described in detail hereafter.
Synthesis Examples 7 to 66 follow one of these detailed Examples, but, in
each case, substituting the appropriate starting materials to obtain the
desired product. Specifically, SE 12 follows the general method of SE 3;
other compounds of the formula (Ia) were made by the method of SE 1 or SE
2; carbinol compounds of the formula (Ib)-were made by the method of SE 6;
and ether compounds of the formula (Ib) were made by the method of SE 5.
In the reaction stage ii of SE 1, SE 2, SE 3 and SE 4 as applied to other
compounds the quantity of the lithium compound was adjusted to get a
desired balance of reaction speed, yield (completeness of reaction) and
minimising byproducts.
The nature of the substituents in the Synthesis Examples is detailed in
Table 1 below, in which the following abbreviations are used for
substituent groups:
______________________________________
Me = methyl Et = ethyl Bu = -n-butyl
Bu.sup.t = .sub.- t-butyl
Pe = pentyl Hp = heptyl
Oc = octyl Do = dodecyl Np = naphthyl
cHx = cyclohexyl
cPM = cyclopentyl-
Ind = indol-3-yl
Bz = benzyl methyl
Mor = .sub.-- N-morpholino
Ph = phenyl
Pyr = .sub.-- N-pyrrolidino
Pip = .sub.-- N-piperidino
MPz = .sub.-- N-(4- .sub.-- N-
Pz = .sub.-- N-piperazino
methyl)piperazino
Py = pyridin-4-yl
Cz = carbazol-3-yl
______________________________________
Substitution on groups abbreviated in this way is indicated numerically s
4Me.sub.2 N.Ph = 4dimethylaminophenyl, 2,4Me.sub.2.Ph = 2,4dimethylphenyl
and so on.
TABLE 1
__________________________________________________________________________
Structures of Compounds of Synthesis Examples
SE No
Formula
A.sub.1
A.sub.2 A3 A.sub.4
__________________________________________________________________________
1 Ia Ph Ph 4-Me.sub.2 N.Ph
H
2 Ia 4-Mor.Ph
Ph 4-Me.sub.2 N.1-Np
H
3 Ia Ph Bu.sup.t 4-Me.sub.2 N.Ph
H
4 Ia 4-Pip.Ph
Ph 4-MeO.Ph H
5 Ib 4-Pip.Ph
Ph 4-MeO.Ph Me
6 Ib 4-Pip.Ph
Ph 4-MeO.Ph H
7 Ia 4-Pip.Ph
Ph 4-Me.sub.2 N.Ph
H
8 Ia 4-MPz.Ph
Ph 4-Me.sub.2 N.Ph
H
9 Ia 1-Np Ph 4-Me.sub.2 N.Ph
H
10 Ia 4-Mor.Ph
Ph 4-MeO.Ph H
11 Ia Ph Ph 2-Cl-4-Me.sub.2 N.Ph
H
12 Ia Ph cPM 4-Me.sub.2 N.Ph
H
13 Ia 4-Pip.Ph
Ph 4-BzO-Ph H
14 Ia 4-MeO.Ph
Ph 4-Me.sub.2 N.Ph
H
15 Ia 2-Np Ph 4-Me.sub.2 N.Ph
H
16 Ia 4-Me.sub.2 N.Ph
Ph 4-Pyr.Ph H
17 Ia Ph Ph 2-Me-4-Me.sub.2 N.Ph
H
18 Ia 4-Me.Ph
Ph 4-Me.sub.2 N.Ph
H
19 Ia 4-Mor.Ph
Ph 4-Me.sub.2 N.Ph
H
20 Ia 4-Me.Ph
Ph 2-Cl-4-Me.sub.2 N.Ph
H
21 Ia 4-Ph.Ph
Ph 4-Me.sub.2 N.Ph
H
22 Ia 4-Pip.Ph
Ph 4-PhO.Ph H
23 Ia 4-Cl.Ph
Ph 4-Me.sub.2 N.Ph
H
24 Ib 4-Mor.Ph
Ph 4-MeO.Ph Me
25 Ia 4-Me.sub.2 N.Ph
Ph 4-Me.sub.2 N.Ph
H
26 Ib 4-Me.Ph
Ph 4-Me.sub.2 N.Ph
Me
27 Ia 4-Bu.sup.t.Ph
Ph 4-Me.sub.2 N.Ph
H
28 Ia 4-MPz.Ph
Ph 4-MeO.Ph H
29 Ia 4-Pip.Ph
Ph Ph H
30 Ia 4-Pip.Ph
Ph 4-EtO.Ph H
31 Ib 4-Me.Ph
Ph 4-Me.sub.2 N.Ph
4-NO.sub.2.Ph
32 Ia 4-Pip.Ph
Ph 1-Np H
33 Ia 4-cHx.Ph
Ph 4-Me.sub.2 N.Ph
H
34 Ia 4-Pip.Ph
Ph 9-Et.Cz H
35 Ia 4-Pip.Ph
Ph 4-Me.Ph H
36 Ib 4-Mor.Ph
Ph 4-MeO.Ph Et
37 Ia 4-Me.sub.2 N.Ph
Ph 4-MeO.Ph H
38 Ia 4-Pip.Ph
4-Me.Ph 4-MeO.Ph H
39 Ia 4-Ph.Ph
Ph 4-Pyr.Ph H
40 Ia 4-Mor.Ph
Ph 1-Np H
41 Ia 4-Mor.Ph
Ph Ph H
42 Ib 4-Me.Ph
Ph 4-Me.sub.2 N.Ph
H
43 Ia 4-Pip.Ph
Ph 9-Bu.Cz H
44 Ia 4-Pip.Ph
4-MeO.Ph 4-MeO.Ph H
45 Ia 4-Me.sub.2 N.Ph
Ph 3-MeO-4-DoO.Ph
H
46 Ia 4-Pip.Ph
Ph 4-Py H
47 Ia 4-Me.sub.2 N.Ph
Ph 4-HpO.Ph H
48 Ia 4-Mor.Ph
Ph 4-MeO.1-Np
H
49 Ia 4-Me.sub.2 N.Ph
Ph 9-Bu.Cz H
50 Ia 4-Me.sub.2 N.Ph
Ph 4-PeO.Ph H
51 Ia 4-Mor.Ph
Ph 9-Bu.Cz H
52 Ib 4-Pip.Ph
Ph 4-MeO.Ph Ph
53 Ia 2-Me.Ph
Ph 4-Me.sub.2 N.Ph
H
54 Ia 2,4-Me.sub.2.Ph
Ph 4-Me.sub.2 N.Ph
H
55 Ia 4-MeO.Ph
Ph 4-(MePhN).Ph
H
56 Ia 4-MeO.Ph
Ph 4-(Me H
(4-MeOPh)N).Ph
57 Ia 4-Me.sub.2 N.Ph
Ph .sub.-- N-Me-2-Ph.Ind
H
58 Ia 4-MeO.Ph
Ph 4-(Bz.sub.2 N).Ph
H
59 Ia 4-MeO.Ph
Ph 2-Cl-4-Et.sub.2 N.Ph
H
60 Ia 4-MeO.Ph
Ph 4-Et.sub.2 N.Ph
H
61 Ia 4-MeO.Ph
Ph 4-Pip.Ph H
62 Ia 4-MeO.Ph
Ph 4-Pyr.Ph H
63 Ib 4-MeO.Ph
Ph 4-(MePhN).Ph
H
64 Ib 4-MeO.Ph
Ph 4-Me.sub.2 N.Ph
H
65 Ib 4-MeO.Ph
Ph 4-(MePhN).Ph
Me
66 Ib 4-MeO.Ph
Ph 4-Me.sub.2 N.Ph
Me
67 Ia 4-MeO.Ph
H 4-(MePhN).Ph
H
68 Ia 4-MeO.Ph
H 4-Me.sub.2 N.Ph
H
__________________________________________________________________________
In the Synthesis Examples and in Table 2 below, melting points are open
capillary uncorrected values. Compounds for which no melting point is
given were obtained as oily products or amorphous solids and were not
purified. Generally, these products were fairly pure (many gave easily
readable IR and NMR spectra) but may have contained impurities or residual
solvent. Yield figures are % of the theoretical maximum on the limiting
intermediate precursor i.e. values are for the final step of the
synthesis. NMR spectra were run on a Hitachi Perkin-Elmer R600 NMR
spectrometer at 60 MHz generally in deuterochloroform using tetramethyl
silane (TMS) as internal standard. Sometimes, perdeuterobenzene (C.sub.6
D.sub.6) and for one sample dimethylsulphoxide (DMSO) were used as the
solvent using TMS as internal standard. Infra red (IR) spectra were run on
a Perkin-Elmer 728 Infra red spectrophotometer. The IR samples were
prepared as thin films generally from chloroform (CHCl.sub.3 or
CDCl.sub.3) solution and evaporating the solvent. The IR spectra obtained
showed no appreciable signs of residual solvent, in particular the
characteristic peaks of CHCl.sub.3 at ca. 2400 cm.sup.- 1 and CDCl.sub.3
at ca. 2220 cm.sup.-1 were absent or not significantly above the baseline.
Occasionally carbon tetrachloride was used as the solvent or the IR was
run on a thin film of a hydrocarbon oil (Nujol) mull of the solid
compound.
The intermediate vinyl ketones referred to in the Synthesis Examples below,
were also analysed by NMR and IR spectroscopy. The results afforded
further, if indirect, evidence for the structures of the chromogenic
compounds of the general formula (I).
SYNTHESIS EXAMPLE 1
1,1-Diphenyl-3-(4-dimethylaminophenyl)prop-2-en-1-ol
i. 1-Phenyl-3-(4-dimethylaminophenyl)-1-oxo-prop-2-ene
Acetophenone (28.0 g, 0.15 mole) and 4-dimethylaminobenzaldehyde (22.35 g,
0.15 mole) were dissolved in methanol (150 ml) in a 500 ml, 3-necked round
bottom flask. The flask was wrapped in aluminium foil to exclude light and
was fitted with a mechanical stirrer and a water cooled condenser. The
third neck was stoppered and used to obtain samples for monitoring during
the reaction. Aqueous sodium hydroxide solution (50 ml of 30% w/v) was
added dropwise to the vigorously stirred clear methanolic solution. A
yellow/orange solid started separating from the reaction solution (which
had turned orange) after about 24 hours. Stirring was continued for about
48 hours at ambient temperature and the intermediate title compound was
isolated by vacuum filtration, washed successively with water, methanol
and petroleum ether (40-60.degree. C.) and dried in vacuo to give 23.3 g
(62% of theory) of 1-phenyl-3-(4-dimethylaminophenyl)-1-oxo-prop-2-ene
with a melting point of 112-114.degree. C.
ii. 1,1-Diphenyl- 3-(4-dimethylaminophenyl)prop-2-en-1-ol
1-Phenyl-3-(4-dimethylaminophenyl)-1-oxo-prop-2-ene (11.79 g, 0.047 mole)
prepared in stage i above was dispersed in sodium dried diethyl ether (200
ml) in a 11 3-necked round bottom flask fitted with a magnetic stirrer and
a water cooled condenser itself fitted with a guard tube containing silica
gel to prevent the ingress of moisture. The side necks were closed with
rubber septa and the system purged with dry nitrogen via a needle through
one of the septa. Phenyl lithium (29.5 ml of a 2M solution in
cyclohexanediethyl ether, 0.059 mole i.e. a 25% molar excess) was added
using a syringe through the other septum while the contents of the flask
were vigorously stirred using the magnetic stirrer and a slow steady
stream of dry nitrogen maintained through the apparatus. The addition of
the phenyl lithium caused the colour of the reaction mix to change from
orange to green. After completion of the addition of phenyl lithium the
reaction mixture was kept stirred at ambient temperature for 4 hours and
the progress of the reaction was monitored by tlc on silica plates eluted
with 1:1 (v/v) ethyl acetate petroleum : ether (40-60.degree. C.) on
samples of the reaction mix.
When the reaction was complete, water (300 ml) was added carefully to the
reaction mix to quench residual phenyl lithium and liberate the product
carbinol. This resulted in a two-phase mixture. The organic phase
contained most of the colour former, but a certain amount was assumed to
be present in the aqueous phase. The two phases were separated, and the
aqueous layer was extracted with diethyl ether (3.times.200 ml). The
resulting ether extracts were combined with the organic phase referred to
above, and the whole was dried over anhydrous sodium sulphate. The ether
was removed using a rotary evaporator leaving the crude solid title
compound. The crude product was recrystallized from petroleum ether
(40-60.degree. C.) : toluene (9:1 v/v) to give
1,1-diphenyl-3-(4-dimethylaminophenyl)prop-2-en-1-ol as a buff coloured
solid in a yield of 6.96 g (45% of theory) with a melting point of
117-118.4.degree..
SYNTHESIS EXAMPLE 2
1-phenyl-1-(4-N-morcholinophenyl)-3-(4-dimethylamino
naphth-1-yl)prop-2-en-1-ol
i. 1-(4-N-morpholinophenyl)-3-(4-dimethylaminonaphth
1-yl)-l-oxo-prop-2-ene
The intermediate title compound, having a melting point of 153-155.degree.
C., was made by the general method set out in Synthesis Example 1 but
using 4-N-morpholinoacetophenone and 4-dimethylamino-1-naphthaldehyde as
the starting materials.
ii 1-Phenyl-1-(4-N-morpholinophenyl)-3-(4-dimethylamino
naphth-1-yl)prop-2-en-1-ol
Sodium dried ether (50 ml) was placed in a 3-necked 11 round bottom flask
fitted with a mechanical stirrer, water cooled condenser and calcium
chloride drying tube, and a dropping funnel containing bromobenzene (6.1
g, 0.039 mole). Lithium metal (0.54 g, 0.078 mole) cut into small pieces
was put into the flask and a few crystals of iodine were added. A portion
of the bromobenzene (ca. 0.5 g) was added to the reagents in the flask and
the mixture was warmed gently without stirring until reaction began. The
mixture was then stirred and the remaining bromobenzene added dropwise.
The reaction mixture was stirred for 30 minutes after the addition of
bromobenzene was complete, by which time all of the lithium had reacted. A
solution of
1-(4-N-morpholinophenyl)-3-(4-dimethylaminonaphth-1-yl)-1-oxo-prop-2-ene
(5 g, 0.013 mole), made in stage i above, in sodium dried benzene (200 ml)
was added to the phenyl lithium solution in the flask in portions
(4.times.50 ml). The orange-yellow solution was stirred at ambient
temperature for 1 hour, by which time the colour had changed to pale
yellow. TLC on the reaction mixture using 1:1 (v/v) ethyl acetate :
petroleum ether (40-60.degree. C.) as eluent showed that the reaction was
complete.
The title compound was recovered by adding water (100 ml) dropwise to the
reaction mixture to quench excess phenyl lithium and release the carbinol
and the mix was stirred for a further 30 minutes at ambient temperature.
The organic layer was then separated, washed with water (3.times.50 ml),
dried over magnesium sulphate and the solvent removed on a rotary
evaporator to give a sticky yellow solid. This crude product was
recrystallized from a mixture of toluene and petroleum ether
(40-60.degree. C.) (1:9 v/v) to give
1-phenyl-1-(4-N-morpholinophenyl)-3-(4-dimethylaminonaphth-1-yl)prop-2-en-
1-ol as a pale cream crystalline solid in a yield of 3.3 g (55% of theory)
with a melting point of 112-115.degree. C.
SYNTHESIS EXAMPLE 3
1-t-Butyl-1-phenyl-3-(4-dimethylaminophenyl)prop-2-en-1-ol
i. 1-N-Butyl-3-(4-dimethylaminophenyl)-1-oxo-prop-2-ene
t-Butylmethylketone (pinacolone) (10 g, 0.1 mole) and
4-dimethylaminobenzaldehyde (14.9 g, 0.1 mole) were dissolved in methanol
(100 ml) and reacted with aqueous sodium hydroxide solution (50 ml of 30%
w/v) under the conditions described in SE 1. During the reaction the clear
methanolic solution turned yellow. Stirring was continued for 48 hrs at
ambient temperature, by which time a yellow solid had separated from the
reaction mixture. The intermediate title compound was isolated as
described in SE 1 to give 4.72 g (20% of theory) of
1-N-butyl-3-(4-dimethylaminophenyl)-1-oxo-prop-2-ene, having a melting
point of 71.5.degree. C.
ii. 1-N-Butyl-1-phenyl-3-(4-dimethylaminophenyl)-prop-2-en-1-ol
1-t-Butyl-3-(4-dimethylaminophenyl)-1-oxo-prop-2-ene (4 g, 0.017 mole)
prepared in stage i above was reacted with phenyl lithium (made from
lithium; 0.73 g, 0.105 mole, and bromobenzene; 8.2 g, 0.052 mole) under
the conditions described in SE 2 above. The title compound was isolated
and recrystallized as described in SE 2 to give
1-N-butyl-1-phenyl-3-(4-dimethylamino-phenyl)prop-2-en -1-ol as a cream
solid at a yield of 41% of theory, having a melting point of
105-106.degree. C.
SYNTHESIS EXAMPLE 4
1-Phenyl-1-(4-N-piperidinophenyl)-3-(4-methoxyphenyl)-prop-2-en-1-ol
The title compound was made by the general method described in SE 1 but
substituting 4-N-piperidinoacetophenone and 4-methoxybenzaldehyde for the
acetophenone and 4-dimethylaminobenzaldehyde used in SE 1. The solid
product was obtained at 52% (of theory) yield, having a melting point of
114-116.degree. C.
SYNTHESIS EXAMPLE 5
1-Phenyl-1-(4-N-piperidinophenyl)-3-(4-methoxyphenyl)-prop-1-en-3-methoxide
1-Phenyl-1-(4-N-piperidinophenyl)-3-(4-methoxyphenyl)prop2-en-1-ol (2.0 g,
5.times.10.sup.-3 mole) made as described in SE 4 was dispersed in
analytical purity (dry) methanol (150 ml) under stirring at ambient
temperature. Dry HCl gas was bubbled through the dispersion until all the
starting material had dissolved to give a blue solution. Solid sodium
methoxide was then added to the solution in small portions (very roughly
50 mg per portion) by means of a spatula until the solution became
colourless. Water (250 ml) was then added with stirring to quench any
excess methoxide and the reaction mixture was extracted with chloroform
(250 ml). The chloroform extract was dried over magnesium sulphate and the
solvent was removed on a rotary evaporator to give ca. 2 g (ca. 96% of
theory) of 1-phenyl-1-(4-N-
piperidinophenyl)-3-(4-methoxyphenyl)prop-1-en-3-methoxide as a yellow
oil.
The NMR spectrum indicated that the product is almost certainly a mixture
of cis- and trans-isomers (probably about 50:50).
SYNTHESIS EXAMPLE 6
1-Phenyl-1-(4-N-piperidinophenyl)-3-(4-methoxyphenyl)-prop-1-en-3-ol
1-Phenyl-1-(4-N-piperidinophenyl)-3-(4-methoxyphenyl)prop2en-1-ol (0.5 g,
1.25.times.10.sup.-3 mol) made as described in SE 4 dissolved in a mixture
of ether (100 ml) and water (100 ml). Dilute hydrochloric acid (2M, an
excess) was added to the mixture dropwise and stirring was continued for
30 minutes after the acid addition was completed. Aqueous sodium hydroxide
solution (10M) was then added dropwise to the stirred mixture until the
mix became colourless and stirring was continued for a further hour to
ensure complete reaction (probably not necessary as colour loss is
expected to indicate complete reaction). The ethereal layer was then
separated, washed with water (2.times.100 ml), dried over magnesium
sulphate and the ether removed on a rotary evaporator to give
1-phenyl-1-(4-N-piperidinophenyl)-3-(4-methoxyphenyl)prop-1-en-3-ol as an
oil.
SYNTHESIS EXAMPLES 7 to 66
Further compounds of the general formula I were made by the methods of SE 1
to SE 6 as specified above. The structures of these compounds (and those
of SE 1 to SE 6) are set out in Table 1 above.
SYNTHESIS EXAMPLE 67
This illustrates the synthesis of a chromogenic compound of formula (I) in
which Az is hydrogen, namely
1-(4-methoxyphenyl)-3-(4-dimethylaminophenyl)prop-2-en-1-ol, by reduction
of a chalcone with sodium borohydride in methanol according to the
following reaction sequence:
##STR10##
1-(4-methoxyphenyl)-3-(4-dimethylaminophenyl)-1-oxo-prop-2-ene (14.1 g,
0.05 mol) was dispersed in methanol (100 ml). Sodium borohydride (5.6 g,
0.15 mol) was added slowly at ambient temperature under vigorous stirring.
After completion of the addition of sodium borohydride the reaction
mixture was kept stirred at ambient temperature for 5 hours. When the
reaction was complete, the reaction mixture was poured into water (500
ml), and extracted with toluene. The toluene was removed using a rotary
evaporator leaving an oily residue. The crude product was crystallized
from methanol to give
1-(4-methoxyphenyl)-3-(4-dimethylaminophenyl)prop-2-en-1-ol as a white
coloured solid in a yield of 4.0 g (28.3% of theory) with a melting point
of 137-148.degree. C.
SYNTHESIS EXAMPLE 68
This illustrates the syntheses of a further chromogenic compound of the
formula (I) IN WHICH A.sub.2 is hydrogen, namely
1-(4-methoxyphenyl)-3-(4-phenylmethylaminophenyl)prop-2-en1-ol, by a
method analogous to that of SE 67 and according to the following reaction
sequence:
##STR11##
1-(4-methoxyphenyl)-3-(4-phenylmethylaminophenyl)-1-oxoprop-2-ene (13.7 g,
0.04 mol) was dispersed in methanol (100 ml). Sodium borohydride (4.1 g,
0.11 mol) was added slowly at ambient temperature under vigorous stirring.
After completion of the addition of sodium borohydride, the reaction
mixture was kept stirred at ambient temperature for 20 hours. When the
reaction was complete, the reaction mixture was poured into water (500
ml), and extracted with toluene. The toluene was removed using a rotary
evaporator leaving an oily residue. The crude product was purified from
petroleum ether : toluene (9:1 v/v) to give
1-(4-methoxyphenyl)-3-(4-phenylmethylaminophenyl)prop-2-en-1-ol as an
amorphous solid in a yield of 12.3 g (89.1% of theory).
Table 2 below gives yield and melting point data (where determined) on the
compounds made in SE 7 to SE 68 (even where no data is quoted, the
compounds were actually made, and analysed by IR and/or NMR spectroscopy,
except for SE 3 to 68).
TABLE 2
______________________________________
SE No. Yield (%) m.p. (.degree.C.)
______________________________________
7 7 110-113
8 13 165-172
9 oil
10 90 159-162
11 47 145-149
12 26 62-64
13 13 120-122
14 79 82-83
15 32 118-121
16 15 132-135
17 46 110-114
18 57 105-107
19 21 oil
20 51 137-138
21 15 151-154
22 oil
23 48 104-105
24 oil
25 8 88-90
26 oil
27 oil
28 60 165-166
29 18 118-121
30 18 119-123
31 oil
32 137-140
33 53 101-103
34 oil
35 44 125-130
36 oil
37 oil
38 oil
39 38 102-103
40 48 185-188
41 47 157-160
42 oil
43 oil
44 oil
45 oil
46 oil
47 oil
48 94 141-142
49 oil
50 oil
51 oil
52 oil
53 39 114-115
54 32 116-119
55 64 160-163.5
56 oil
57 22 159-168
58 1.4 amorphous solid
59 65 99-103
60 79 97-103
61 amorphous solid
62 29.8 98-114
63 amorphous solid
64 amorphous solid
65 amorphous solid
66 amorphous solid
67 28.3 amorphous solid
68 89.1 137-148
______________________________________
APPLICATION EXAMPLE 1
Each f the compounds made in the Synthesis Examples was tested by making up
a solution (1% w/v) in a 2:1 (v/v) mixture of partially hydrogenated
terphenyl (Santasol 340 from Monsanto) and kerosene (Exxsol form Exxon
Chemicals) and coating the solution by means of a laboratory gravure hand
coater onto inorganic clay CF paper, utilising montmorillonite colour
developer as the active component. The coloured image produced was allowed
to develop in the dark for 48 hours and was then assessed visually for
colour (hue) and for most compounds the UV-visible spectrum (in the range
of ca. 350-750 nm) was taken on a Philips PU 8800 UV-visible
spectrophotometer. The .lambda. max values of the main absorption
peak/band was measured instrumentally together with the peak locations of
subsidiary peaks at significantly different wavelengths. From the plotted
spectrum the bandwidth range at 1/2 maximum peak height (1/2 ht range) was
measured (to the nearest 5 nm). For some compounds, the image intensity
(Int.) of such samples was assessed visually i.e. in effect by visual
comparison with known colour formers with the results being quoted on a
ranking scale of 5 (most intense) to 1 (least intense), and the fade
performance assessed by exposing similarly prepared samples to light in a
fade cabinet (effectively a tray strongly illuminated in a standard
fashion with light from fluorescent tubes) for periods of 0, 1, 3, 5 and
24 hours. Fade is assessed visually (effectively by comparison with known
controls) with the results being quoted on a ranking scale of 5 (least
fade) to 1 (most fade). The results of these tests are set out in Table 3
below. For compounds of the invention recovered as oily products, the
image intensity and 1/2 peak height bandwidth figures may underrecord the
performance of the compounds because the presence of impurities or
residual solvent reduces the amount actually present in solution. For
comparison, CVL gives a blue colour on the CF with .lambda. max at 616 nm,
a 1/2 height peak width of ca. 125 nm (525-650 nm) an intensity ranking of
4 and a fade ranking of 2.
TABLE 3
______________________________________
Summary of Testing in Application Example 1
1/2 ht.
SE max range
No Colour (nm) (nm) Int. Fade
______________________________________
1 red-magenta 528 440-620 5 4
2 blue 744 535-805 4 3
3 yellow 470 <350-550 5 5
4 blue 595 490-680 4 5
5 blue 595 490-680 4 5
6 blue 595 520-675
7 green 741 650-780 4 2
(465)
8 blue 628 510-740 4 2
9 red-magenta 543 450-610 2 2
10 blue-cyan 652 515-690 4 4
(434)
11 blue-magenta 560 455-640
12 orange-red 508 420-590 3 3
13 blue 587 480-670 5 3
14 blue 590 480-675 5 5
15 blue-magenta 562 460-645 3 2
16 green 737 640-780 4 3
(462)
17 red-magenta 525 440-610
18 blue-magenta 562 480-645 5 5
19 cyan 725 590-765 4 3
(458)
20 reddish-blue 577 480-655 5 3
21 magenta 556 460-625 5 4
22 reddish-blue 579 480-660 4
23 red-magenta 526 450-605 5 5
24 blue-cyan 653 515-700
(434)
25 green 737 630-780 4 3
(460)
26 blue-magenta 597 460-630
27 magenta 557 470-630 3 4
28 cyan 644 585-675 3 2
(451)
29 red-magenta 527 445-615 4 2
30 blue 595 485-685 5 5
31 magenta 562 460-640
32 reddish-blue 590 500-670 2 2
33 magenta 560 460-635 5 4
34 cyan 719 595-735 4 3
(456)
35 blue-magenta 566 465-640 5 3
36 blue 653 540-685
37 blue
38 blue 595 505-675 3 3
39 magenta 546 450-650 3 4
40 blue 619 515-695 4 2
41 magenta 560 470-630 4
42 magenta 560 460-640
43 cyan 718 600-755 3 3
44 blue 606 495-580
45 blue 590 505-670 4 3
46 orange 480 405-545
(730)
47 blue 590 510-765 3 2
48 cyan 718 605-765 5 4
(478)
49 cyan 688 .about.500-765
4
(354)
50 blue 595 505-675 4 3
(636)
51 cyan 727 650-760 3 2
52 blue 596 515-670
53 magenta 521 445-610
54 magenta 530 450-620
55 blue 650 530-687 5 5
(605)
56 blue 650 532-692 3 4
(610)
57 yellow-green 675 642-700 3 3
58 blue 658 532-690 3 3
(610)
59 blue 655 530-687 4 5
(605)
60 purple 595 502-647 4 5
61 purple 598 502-670 3 4
62 purple 595 515-645 4 5
63 blue 650 5 5
(605)
64 purple 589 4 5
65 blue 650 5 5
(605)
66 purple 589 4 5
67 blue 580
68 purple 560
______________________________________
For SE 67 and SE 68, intensity and fade testing was carried out and the
results were satisfactory. However, the testing and ranking procedure
described earlier was not followed, and so no data is quoted.
APPLICATION EXAMPLE 2
The chromogenic compounds of SE Nos. 1, 3, 4, 10, 11, 17, 18, 19, 23, 53
and 54 were each separately encapsulated i.e. as single colour formers, in
solution in 2:1 (v/v) partially hydrogenated terphenyl (Santosol 340) and
kerosene (Exxsol) using the aminoplast encapsulation technique described
in British Patent No. 1507739.
The chromogenic compounds of SE Nos. 55 to 57 and 59 to 62 were each
separately encapsulated by a gelatin coacervation technique as described
in British Patent No. 870476 in the same solvent blend as above. The
capsule emulsions were each hand coated onto base paper using
carbomethoxycellulose as binder and a mixture of wheatstarch and cellulose
floc as agents for preventing premature capsule rupture. The CB sheets
thus formed were calendered against inorganic clay CF sheets as described
in AE1 to give coloured images. In each case the chromogenic compounds
were encapsulated successfully and gave capsule emulsions which were
substantially colourless (white) or (in the case of SE 19) pale blue.
Thus, the chromogenic compounds did not significantly colour up
prematurely under the conditions used in the encapsulation process. The
coloured images produced on the CF paper matched the colours and/or
spectral data given in Table 3 above.
APPLICATION EXAMPLE 3
The chromogenic compound of SE 18 was formulated with other (conventional)
chromogenic compounds as follows:
______________________________________
Chromogenic compound amount (% w/v)
______________________________________
CVL 0.43
9- .sub.-- N-butylcarbazol-3-yl-bis(4- .sub.-- N-methyl-
0.4
.sub.-- N-phenylaminophenyl)methane
Compound of SE 18 0.5
3'-iso-propyl-7-dibenzylamino-2,2'-
0.7
spirobi-[2 .sub.-- H-1-benzopyran]
3- .sub.-- N-ethyl- .sub.-- N-(4-methylphenyl)amino-
0.9
7- .sub.-- N-methyl- .sub.-- N-phenyl-aminofluoran
3-diethylamino-7-chloro-6-methylfluoran
0.3
2(3,4-dioctyloxyphenyl)ethen-2-ylquinoline
0.7
______________________________________
This formulation was dissolved in 1:1 (v/v) partially hydrogenated
terphenyl (Santosol 340) and kerosene (Exxsol) at a total chromogenic
material concentration of 3.93% (w/v) and encapsulated as described in AE
2. The capsule emulsion was hand coated onto base paper as described in AE
2 and imaged, by calendering, typing, impact printing or writing against
inorganic clay CF as used in AE 1 to give a good black copy image on the
CF.
APPLICATION EXAMPLE 4
The chromogenic compounds of SE Nos. 3 and 4 were combined in a weight
ratio of ca. 2:1 to make a chromogenic material formulation that was
dissolved (at a total chromogenic material concentration of ca. 5% w/v) ,
encapsulated and coated as described in AE 2. This CB paper was imaged
against inorganic clay CF as used in AE 1 to give a stable black copy
image. Initially the image was blue, because the chromogenic material of
SE 3 developed colour more slowly than that of SE 4, but gradually turned
black. This Example illustrates the breadth of the absorption bands of the
chromogenic compounds of the invention in that two chromogenic compounds
suffice to generate a stable black image on an inorganic clay CF. Typical
current commercial products use several chromogenic compounds to achieve
black copy images on inorganic clay CF.
APPLICATION EXAMPLE 5
This demonstrates the suitability of the chromogenic compounds of formula
(I) for use in heat-sensitive record material.
Three different thermally-sensitive coating formulations were prepared in
conventional manner using the chromogenic compounds of SE 4, SE 10 and SE
18, polyvinyl alcohol, a bisphenolic coreactant and other components
conventional in heat-sensitive record material. The formulations were
separately applied to base paper by means of a laboratory Meyer bar
coater, and the thus-coated paper was dried. On application of a thermal
stylus, coloured images were formed (blue for the SE 4 formulation,
yellow-green for the SE 10 formulation, and pale purple for the SE 18
formulation).
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